Rewrite ${\dfrac{7^{-12}}{7^{-7}}}$ in the form ${7^n}$.
${ \dfrac{7^{-12}}{7^{-7}} = 7^{-12-(-7)}} $ ${ \hphantom{\dfrac{7^{-12}}{7^{-7}}} = 7^{-5}} $